It is proposed to investigate PKC conformational change upon diacylglycerol (DAG) and 12-0-teradecanoylphorbol-1-3-0-acetate (TPA) activation using intrinsic tryptophan fluorescence decay, to test the hypothesis that DAG and phorbol esters bind to PKC at different sites and produce distinct conformation of PKC. Studies also encompass investigations of conformational changes upon interactions with lipid bilayers.